A so called “roll off” dumpster is usually an open top rectangular container equipped with wheels to facilitate placement and removal of the dumpster. Construction debris may originate from a building site where something is being built, renovated, or demolished. Roll-off dumpsters are used for moving material away from a work site. The material in the roll off may be taken to a landfill, recycled, or disposed/recovered in some other way.
The debris container of a roll off dumpster is typically an open top rectangular reinforced steel box designed to be transported by special roll-off trucks. Some roll-off dumpsters have a swinging door on one longitudinal end to facilitate loading and disposal of waste. Roll-off containers typically have a rectangular footprint typically determined by the size of typical trucks. Roll-off container sizes are determined by the amount of volume of debris they contain. Typical container sizes in the United States are 10, 15, 20, 30, and 40 cubic yards. A typical 40 cubic yard container may, for example, be 6′ 5″ high by 21′6″ long and 8′ 6″ wide and may have a load limitation imposed by a rental entity of six tons. Even larger 100 yard containers that measure 8′ wide, 48′ long and 136″ high are also available. Weight limits are necessary to ensure compliance with road-use and safety laws and regulations as well as the integrity of the container and truck. Large roll off dumpsters typically have four metal roller-shaped wheels disposed at the corners of the rectangular container. Smaller roll off dumpsters have two wheels on one end and a pair of runners at the opposite end of the container. Roll-off dumpsters are placed by roll-off trucks equipped with a hydraulically operated bed and rails arranged to align with the wheels. The bed is raised and a cable is used to slowly lower the container until the rear-most pair of wheels contacts the ground. After the waste container is loaded with debris, the roll-off truck pulls the filled container onto the roll-off truck by using a cable and winch system. Some roll-off trucks may employ a hook-lift system.
Front load dumpsters are also relevant to the disclosure. Front load dumpsters are commonly used for waste handling at businesses, condominiums and apartment complexes. Front load dumpsters typically include sliding doors for waste disposal and pivoting covers to enclose the top of the container. Front load dumpsters include channels open toward the front of the dumpster that are engaged by two large elongated forks extending generally forward of the cab of the truck. Front load dumpsters are emptied by inserting the forks into the channels and hydraulically raising the dumpster to tip the contents into the waste bin of the truck, then lowered again. Front load dumpsters rest on box shaped steel tubing extending across the bottom of the debris container.
One problem often encountered with roll-off dumpsters as well as front load dumpsters is liability for damaging the surface on which the container is placed. Most dumpsters are placed by necessity on paved surfaces such as asphalt or concrete. Damage to the surface on which the container is placed, such as a concrete or asphalt paved surface, may occur during placement, removal or even when the container merely rests on the surface for an extended period of time. It will be understood that such containers are often very heavy when empty and extremely heavy when loaded. The damage to asphalt surfaces is most extreme in warm weather occasions which soften the asphalt.
The use of cylindrical wheels to support such containers on a planar support surface result in a line contact between the cylindrical wheel and the support surface. Cylindrical wheels and narrow steel rails concentrate the force of the dumpsters on the support surface in a small surface area, which can damage the surface. Any backward or forward movement of the truck during placement increases the surface area that is damaged. It is also possible for wheel-supported dumpsters to roll on an inclined surface, which can be very dangerous to persons and traffic in the vicinity. The box tubes on the bottom of front load dumpsters tend to rust due to ground contact, leaving rust stains on the support surface. Rusted out support tubes must eventually be replaced.
It is common for dumpster companies and property owners to use wood sheets or blocks to support a dumpster and prevent damage to the support surface. Trucks used to deliver, retrieve and empty dumpsters are typically operated by a single driver/operator, so one problem with this approach is that the operator of the truck used to place the container cannot see the precise location of the plywood at the time of container placement. This can result in the dumpster missing the wood, and may necessitate the operator getting in and out of the vehicle cab several times when dropping off a dumpster. Further, the blocks or wood sheets must be delivered with the dumpster, and the dumpster trucks do not typically have room to safely store and transport such materials. It is not permitted to have such heavy objects loose in the cab of the truck.
There is a need in the art for apparatus and methods to reduce the potential damage to paved support surfaces that can result from the use of dumpsters.